JPS60201030A - Method of lowering idle noise - Google Patents

Abstract

PURPOSE:To lower the noise at the time of idling, by closing a suction pipe or exhaust pipe with a slight path remaining when idling is carried out. CONSTITUTION:A suction pipe 5 of an engine is provided with a butterfly valve 10, and when idling is carried out, the suction pipe 5 is closed with a slight and minimum path remaining that is required for combustion. Thus, the explosion power is weakened, and the noise is lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for reducing the noise generated during idling of an internal combustion engine.

Internal combustion engines may perform idle-link operation in which they rotate at low speeds with no load. In the case of a work machine, the work is stopped but the engine is running, and in the case of a car, the engine is running but the car is stopped. In the case of internal combustion engines, noise during operation or running tends to be tolerated to some extent, but Ai!・The noise during the ring is quite worrisome. In particular, tasel engines have the disadvantage of being louder than ganlin engines.

An object of the present invention is to provide a conventional idle noise reduction method that reduces idle noise with a simple configuration.
JI, there is something to do.

The idle noise (4-low 1.) method according to the present invention is characterized by blocking the intake pipe or the exhaust pipe with combustion, leaving a minimum necessary air passage or air gas passage during idling. do.

In the past, in gasoline engines and diesel engines equipped with a 21-inch governor, for example, a throttle valve has been used to block the intake air to some extent during idling. However, these methods are not meant to reduce the idle/l/noise i4, but are methods of supplying the necessary amount of combustion engine, and when it comes to idle noise, this is a method that can be used to reduce idle noise. The reality is that it is not considered because it is low compared to engine noise at normal times.

The present invention aims to further reduce such idle noise and further improve the quietness of the engine, and is particularly suitable for a teasel engine.

Hereinafter, embodiments of the present invention will be described with reference to the drawings for removing wood. In FIG. 1, the second part of the piston 2 that moves reciprocatingly within the cylinder 1 and the cylinder head 3 are shown.

A combustion ¥4 is formed between them. cylinder head 3
Inside, there is an intake pipe 5 that opens into this combustion chamber 4 and a Jul.
A trachea 6 is formed and is normally closed by an inspiratory valve 7 and an inspiratory valve 8, respectively. Intake pump "7"
opens during the downward stroke of the piston 2 and passes through the intake pipe 5 to 7.
Air is taken into the cylinder (2), and the - of histone (2) closes in the ascending stroke, and the air in the cylinder (1) is compressed and heated. Next, near the next top dead center of the piston 2, the fuel injected in the form of a mist from the fuel injection nozzle 9 ignites and explodes, pushing the piston 2 down in one direction. Then, the exhaust valve 8 opens in the vicinity of the piston 2 exceeding the bottom dead center, and the combustion residue in the cylinder 1 is discharged through the exhaust pipe 6. The following is the combustion cycle of a normal tasel engine.

In this heavy-duty diesel engine, at -1' idling, the fuel injection force from the type injection nozzle 1) is suppressed.
- The engine rotates at low speed. However, since enough air is taken in from the intake pipe 5 for combustion, the noise ↑:S at the time of exposure is quite large. As mentioned above, even in a tasel engine equipped with a means such as a 211-machi no Kuganokusu throttle valve, the noise during idling is large. Therefore, in one embodiment of the present invention, the intake of air is limited to the minimum amount necessary for the combustion L, thereby weakening the explosive force during combustion.
This is intended to reduce noise during idling.

The weaker the explosive force, the weaker the piston 2 hits the wall of the cylinder 1, the less the idle noise.
-- further decreases.

The inflow air amount limiting means in the embodiment shown in FIG. 1 is a butterfly valve 10 provided in the intake pipe 5. This valve 1
0 may be a slide valve. This butterfly valve 10 is connected to the intake pipe 5 via a link mechanism 11 having a switch/flange means to close the intake pipe 5 so as to leave a minimum amount of air required for combustion during idling. As a result, although combustion occurs, its explosive power is weakened, so the noise is low.
is operated to keep the butterfly valve 10 horizontal. Although the butterfly valve can be rotated by 1 degree, other means may be used. Although the link mechanism 11 may be operated manually, it is preferable to detect the engine rotation speed and automatically operate the link mechanism 11 by a microconbeater when the idle link state is reached. At this time, if the link mechanism 11 is interlocked with the accelerator pedal so that the butterfly valve 1o gradually opens as the accelerator pedal is depressed, the effectiveness of the engine brake will be improved when the accelerator pedal is released. This butterfly valve 10 is better used if the ganolin engine is equipped with a throttle valve, but if the diesel engine is equipped with a throttle valve, the butterfly valve 10 is installed upstream of this. It is preferable to provide 10. Electronic control technology for controlling such a butterfly valve 10 has been adopted in many automatic tunnels in recent years.
It's a good idea to take advantage of this.

In another embodiment of the invention shown in FIG. 2, I:15,
The intake pipe 5 connects to the butterfly valve 10 during idle link, 1:
However, since the butterfly valve 10 is provided with a small vent hole I2, the minimum necessary air knee for combustion is secured through this vent hole 12. .

In a further embodiment shown in FIG. 3, the intake pipe 5 is likewise completely closed by a butterfly valve 10;
A bypass 13 formed on the wall of the cylinder head 3 so as to bypass the butterfly valve 10 ensures the required amount of air.

The minimum amount of air required for combustion varies depending on conditions such as the engine displacement, compression ratio, length and cross-sectional area of the intake pipe, but generally speaking, the minimum amount of air required for combustion is approximately 1 to 10 times the cross-sectional area of the intake pipe. This can be achieved by ensuring that

FIG. 4 shows an example of the effects of this invention. The engine used in the experiment was Kubota's ER65 type agricultural υ1.
A single-cylinder diesel engine is equipped with a butterfly valve as shown in Fig. 1 in its intake pipe to throttle the intake air.
These are the results measured using Rion Corporation's 5-16 Normal Noise H'' and LR-01FJ level recorder at a remote position. As is clear from this graph, in the conventional state with the butterfly valve open, the noise was about 83 phons during idle link, but by closing the butterfly valve and suppressing the intake air, the noise has been reduced to about 77 phons. .

The above explanation is based on the case where the present invention is applied to an intake pipe, but the same effect can be obtained even if the exhaust pipe 6 is provided with the configuration shown in FIGS. 1 to 3. can get. That is, 4) 1. Since combustion will not occur if the trachea 6 is completely closed, the exhaust pipe 6 is closed by securing the minimum exhaust gas passage necessary for combustion. This reduces explosive force and reduces noise.

As described above, according to the idle engine low F method of the present invention, the intake pipe has a minimum air passage size necessary for combustion during idle link. The explosive force at idling 11.5 is weakened and the explosion noise and crack/big noise are suppressed, and the part 1! Engine wear and damage is reduced, extending the life of the engine.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view of an engine 71' showing one embodiment of the present invention, FIG. 2 is a diagram similar to FIG. 1 showing another embodiment of the invention, and FIG. FIG. 4, a diagram similar to FIG. 1 showing further embodiments of the invention, is a graph showing the effects of the invention. ■･･･ cylinder head, 2 piston, 3 cylinder head, 4 combustion chamber, 5 intake pipe, 6 exhaust pipe, 7 intake valve,
8 exhaust valve, 9 fuel injection nozzle, 10 butterfly valve, II-'J link mechanism, 12 ventilation hole 1 13)
Kuinokusu. Applicant Naobu Imai - Photo - Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. Reduce the noise during idling by closing the intake pipe or exhaust pipe while leaving a small air passage or exhaust gas inlet passage necessary for combustion at the minimum during idling. How to reduce idle noise. 2. The idle noise reduction method according to claim 1, wherein the passage is closed by a valve. :3 The idling noise reduction method according to claim 1, in which the blockage of the passageway is blocked by a valve with a ventilation hole, and the valve is bypassed. A method for reducing idle noise t4 according to claim 1, which is carried out by a bypass.